Portable electronic apparatus having a plurality of card storage portions for removably housing a memory card

ABSTRACT

A portable electronic apparatus has a box-like case. The case includes a peripheral surface having a card insertion port formed therein. A circuit board is housed in the case. First and second card storage portions are respectively arranged on the upper and lower surfaces of the circuit board. The storage portions are arranged at the same position to oppose each other across the circuit board, and respectively have opening portions formed to oppose the card insertion port. A memory card is detachably housed in the first and second card storage portions through the insertion port and the opening portions. The memory card is arranged parallel to the circuit board when the memory card housed in the storage portions.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic apparatus such as aportable computer or a wordprocessor and, more particularly, to astructure for increasing the number of optional units such as a compactdisk drive and a hard disk drive which can be installed in the case ofan electronic apparatus.

2. Description of the Related Art

Various types of high-performance laptop portable computers which can beeasily carried have recently been provided. A computer of this typecomprises a base unit having a keyboard, and a flat panel type displayunit which is mounted on the base unit to be freely opened/closed. Thebase unit has a case consisting of a synthetic resin material.Functional units such as a floppy disk drive and a power supply unit anda circuit board on which various types of circuit parts such as IC chipsare mounted are housed in this case.

In order to prevent an electrical shock and a failure, the case of aconventional computer is designed on the assumption that the case is notdisassembled. The above circuit board and functional units are supportedon the bottom surface of the case. The circuit parts mounted on thecircuit board include parts which generate high-frequency noise whilethey are in operation. It is known that when this high-frequency noiseleaks outside the case, an electric wave trouble or a communicationtrouble may be caused. For this reason, the inner surface of the case isplated with a conductive material or the circuit board is enclosed witha metal shield plate.

Since a computer of this type is used in a variety of applications, itoften has only the minimum necessary functions required for theoperation of a computer. For this reason, various types of optionalunits for functional expansion such as a large-capacity hard disk drive,an expansion card, and a modem unit for communication are prepared for aconventional computer. Such a computer is designed to selectively mountthese optional units in accordance with application purposes. Morespecifically, a storage space for storing optional units is partlyensured in the rear or side portion of a case. This storage space hasinsertion ports formed in the bottom or rear surface of the case. Eachinsertion port is closed by a detachable cover.

According to this arrangement, however, since a storage space foroptional units is partly formed in the interior of the case, the caserequires partition walls to define the storage space. For this reason,the structure of the case is complicated, and the manufacturing costincreases. The interior of the case is narrowed because of the presenceof the partition walls, and escapes for bypassing the partition wallsmust be provided for a circuit board. In addition, the partition wallsinterfere with arrangement of various components.

As the number of optional units which can be additionally mountedincreases, a larger number of storage spaces must be ensured in thecase. Therefore, the number of storage spaces may be limited dependingon the size of a case. Consequently, a large number of optional unitscannot be additionally mounted, interfering with an improvement in theperformance of the computer.

On the other hand, a large-capacity power supply unit and a CPU arehoused in the case of the computer. The power supply unit and the CPUgenerate a large amount of heat while they are in operation. If the heatgenerated by the power supply unit and the CPU remains in the case,peripheral circuit components are greatly affected by the heat. For thisreason, as disclosed in U.S. Pat. No. 4,479,198 issued to Romamo et al.,Oct. 23, 1984, a computer having a functional component generating alarge amount of heat is designed such that an inlet port for drawingouter air and an exhaust port for exhausting the drawn outer air areformed in a side surface of a case, and a cooling fan is arranged in thecase to forcibly cool the functional component.

In addition, as disclosed in U.S. Pat. No. 5,199,888 issued to Condra etat., Apr. 6, 1993, a high-performance computer includes a plurality ofexpansion connectors for connection of various peripheral devices suchas a printer and an external keyboard. These expansion connectors arearranged on a side or rear surface of a case. The expansion connectorsare covered with a connector cover while no peripheral devices areconnected. This connector cover is supported on the case to be movablebetween a closing position at which the expansion connectors are coveredand an opening position at which the expansion connectors are exposed tothe outside of the case.

In the computer having the above arrangement, if expansion connectorsare arranged adjacent to the inlet port or the exhaust port formed inthe case, when the connector cover is moved to the opening position, theconnector cover may overlap the inlet port or the exhaust port. In thiscase, the inlet port or the exhaust port is closed by the connectorcover, and the ventilation in the case is impaired. For this reason, thefunctional component which generates heat cannot be efficiently cooled.

As a portable computer, a computer having a speaker for outputting analarm or warning as a sound during an operation of software is known.The speaker has a speaker frame supporting a cone. This speaker frame issupported on the inner surface of the case.

Various functional components such as a floppy disk drive as well as acircuit board are arranged in the case. In addition, since the internalspace of the case is limited, the circuit board, the functionalcomponents, and the speaker are arranged to be adjacent to each other.For this reason, when the speaker frame is mounted in the case, thefragile cone may interfere with and may be damaged by the circuit boardor a functional component, thus posing a problem in mounting the speakerin the case.

The types of portable computers capable of mounting interface cards forcommunication with external units and application cards storingapplication programs have been increasing. A computer capable ofmounting such a type of card has a card storage portion in the case.This card storage portion has a card insertion port formed in a sidesurface of the case. A connector to which the card is detachablyconnected is arranged in the card storage portion. The connector islocated at the opposite side to the card insertion port.

The card storage portion has an ejector for guides a card, inserted fromthe card insertion port, to the connector, and for ejecting the cardfrom the card storage portion. The ejector has a push button to bedepressed with a finger tip of an operator when the card is to beremoved. The push button is exposed to the card insertion port and islocated adjacent to the rear end portion of the card stored in the cardstorage portion.

According to this arrangement, however, since the push button is exposedto the card insertion port and can be depressed at any time, the pushbutton may be erroneously depressed during an operation of the card. Inorder to prevent this, a known computer is designed such that a lockpawl which is locked to the trailing end of a card inserted from thecard insertion port of the case is arranged at the card insertion port.According to this arrangement, since the card is locked/held in the cardstorage portion by the lock pawl, even if the push button is erroneouslydepressed during an operation of the card, removal of the card from thecard storage portion can be prevented.

On the other hand, if the card needs to be removed and an operatorforgets that the card is locked by the lock pawl, he/she may depress thepush button hard. As a result, an excessive force is applied to theejector, causing an ejector failure or damaging the ejector.

If a computer of this type has first and second card storage portionsfor loading a plurality of types of memory cards, in addition to thecard storage portion for the interface card or the application card, apair of card connectors to which memory cards are connected are arrangedin the card storage portions, respectively. These card connectors aremounted on a main circuit board housed in the case.

In this case, in a computer having only one main circuit board, the pairof card connectors are laterally arranged on the main circuit board onthe same plane. Consequently, the first and second card storage portionsare also laterally arranged in the case.

According to this arrangement, however, since the first and second cardstorage portions are laterally arranged, the area occupied by the cardstorage portions in the case becomes extremely large. This poses aproblem in arranging various functional components such as a floppy diskdrive in the case. In addition, the first and second card storageportions have card insertion ports formed in a side surface of the case,and the card insertion ports are elongated in the lateral direction. Asa result, the card insertion ports occupy a larger proportion of theside surface of the case. Therefore, when expansion connectors and thelike are to be arranged on the side surface of the case, the arrangementof the connectors and the like are undesirably limited by the presenceof the card insertion ports.

A portable computer has a display unit having a display. As disclosed inU.S. Pat. No. 5,103,377 issued to Kobayashi et al., Apr. 7, 1992 or U.S.Pat. No. 5,090,913 issued to Kobayashi, Feb. 25, 1992, this display unitis supported on the case to be pivotal between a closing position atwhich the unit covers a keyboard disposed on the upper surface of thecase and an opening position at which the unit stands upright behind thekeyboard. The display unit has leg portions extending toward the case,and the case has leg mount portions for receiving the leg portions. Theleg portions are pivotally coupled to the leg mount portions via hingemechanisms. In addition, the display is electrically connected to acircuit board, arranged in the case, via a cable. The cable is arrangedbetween the leg portions and the leg mount portions. In thisarrangement, the inner surface of the display unit including the legportions and the inner surface of the case are covered with conductivelayers. With this structure, noise from the cable for handlinghigh-speed electrical signals can be sealed in the computer.

However, there are spaces between the leg portions and the leg mountportions, and the cable is exposed to the outside through these spaces.For this reason, in spite of the fact that the display unit and the casehave an electromagnetic shield function, noise generated by the cablesometimes leaks to the outside of the computer through the spaces,posing a problem in realizing countermeasures against electromagneticnoise.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the abovesituation, and has as its first object to obtain a structure, in aportable electronic apparatus capable of mounting optional units in itscase, which can ensure a sufficient space for mounting optional unitswithout impairing the electromagnetic shield function of the case,facilitates additional mounting of optional units, and can simplify thestructure of the case.

It is the second object of the present invention to provide a structure,in a portable electronic apparatus, which can sufficiently ensure theventilation of the interior of a case by preventing a connector coverfrom closing a vent of the case when the connector cover is opened.

It is the third object of the present invention to obtain a structure,in a portable electronic apparatus having a speaker mounted in a case,which facilitates mounting of the speaker and can prevent damage to thespeaker.

It is the fourth object of the present invention to obtain a structure,in a portable electronic apparatus capable of mounting a card-likeelectronic component, which can prevent the card-like electroniccomponent from being erroneously removed while the component is used,and can also prevent an excessive force from being applied to an ejectorfor ejecting the card-like electronic component, thereby preventingdamage to the ejector.

It is the fifth object of the present invention to obtain a structure,in a portable electronic apparatus capable of mounting a plurality ofcard-like electronic components, which allows compact card storageportions for storing the card-like electronic components to be arrangedin a case to realize a reduction in the size of the case, and canincrease the degree of freedom in arranging other components such asconnectors and switches on the peripheral surface of the case.

It is the sixth object of the present invention to obtain a structure,in a portable electronic apparatus having a cable arranged between adisplay unit and a case, which can reliably shield noise leaking fromthe cable.

In order to achieve the first object, according to the presentinvention, there is provided a portable electronic apparatus comprisinga case made of a synthetic resin material, the case including a box-likebody having a detachable bottom cover, and the body and the bottom coverhaving inner surfaces covered with electromagnetic shield means, a maincircuit board housed in the case, the main circuit board partitioningthe case into an upper mount area and a lower mount area, having anupper surface opposing the upper mount area and a lower surface opposingthe lower mount area, and having a circuit component, which generatesnoise during an operation, arranged on the upper surface, a conductiveshield plate covering the lower surface of the main circuit board, theshield plate being electrically connected to the electromagnetic shieldmeans and surrounding the upper mount area together with theelectromagnetic shield means, and an optional component arranged in thelower mount area, the optional component being exposed to the outside ofthe case and capable of being removed from the case when the bottomcover is removed.

According to this arrangement, the lower mount area on which optionalcomponents are arranged is determined by the space defined by the maincircuit board and the bottom cover of the case. For this reason, theentire space below the main circuit board can be used as an expansionspace for the optional components. In addition, since no partition wallsfor defining an expansion space are required in the case, the shape ofthe case can be simplified. In this case, the upper mount area isenclosed with the shield plate and the electromagnetic shield meanswhich are electrically connected to each other. Therefore, noisegenerated by circuit components can be shielded, and leakage of noisefrom the case can be prevented.

Furthermore, according to the above arrangement, when the bottom coveris removed, the entire lower mount area is exposed. For this reason, anoptional component can be easily arranged without disassembling the caseand removing the main circuit board.

In order to achieve the second object, according to the presentinvention, there is provided a portable electronic apparatus comprisinga box-like case having a peripheral surface in which a vent and aconnector exposure port are formed side by side, the vent causing theoutside and inside of the case to communicate with each other, a circuitcomponent which is housed in the case and generates heat during anoperation, and a connector cover arranged on the peripheral surface ofthe case and supported to be movable between a first position at whichthe cover closes the connector exposure port and a second position atwhich the cover overlaps an opening portion of the vent in theperipheral surface to open the connector exposure port, the connectorcover having a communicating hole which communicates with the vent whenthe connector cover is moved to the second position.

According to this arrangement, when the connector cover is moved to thesecond position, the communicating hole of the connector cover serves asa vent. Hence, the vent is not closed by the connector cover. Therefore,the ventilation in the case can be maintained to prevent heat generatedby circuit components from remaining in the case.

In order to achieve the third object, according to the presentinvention, there is provided a portable electronic apparatus comprisinga box-like case including a peripheral surface having a speaker mountportion, various functional components including a circuit board housedin the case, the functional components being arranged adjacent to thespeaker mount portion, and a speaker unit detachably mounted on thespeaker mount portion, the speaker unit including a support paneldetachably mounted on the speaker mount portion and having acommunicating hole for causing the inside and outside of the case tocommunicate with each other, and an inner surface exposed inside thecase, and a speaker supported on the inner surface of the support paneland including a speaker frame and a cone supported on the speaker frameand opposing the communicating hole, the speaker being supported on thesupport panel before the support panel is mounted on the speaker mountportion so that the speaker unit is assembled as one module in advance.

According to this arrangement, the speaker can be mounted on the supportpanel in a wide place outside the case. For this reason, the cone of thespeaker does not easily interfere with functional components in thecase, and good workability can be ensured to reduce damage to the cone,as compared with the case wherein the speaker is mounted, as a singleunit, on the peripheral surface of the case.

In order to achieve the fourth object, according to the presentinvention, there is provided a portable electronic apparatus comprisinga box-like case having a card storage portion in which a card-likeelectronic component can be stored, and a peripheral surface having acard insertion port communicating with the card storage portion, anejector, arranged in the card storage portion, for ejecting thecard-like electronic component from the card storage portion, theejector having an ejector operating member exposed to the card insertionport and located adjacent to the card-like electronic component, and alock member supported on the case to be movable between a first positionat which the ejector operating member is covered and a second positionat which the ejector operating member is exposed, the lock member havinga lock portion which is locked to the card-like electronic componentinserted in the card storage portion when the lock member is moved tothe first position.

According to this arrangement, when a card-like electronic component ismounted in the card storage portion, and the lock member is moved to thefirst position, the ejector operating member is covered with the lockmember to inhibit an operator from depressing the ejector operatingmember with his/her finger tip. This prevents an erroneous operation ofejecting a card-like electronic component from the card storage portionwhile the card is used. In addition, there is no possibility that theoperator pushes the ejector operating member with a large force,forgetting that the card-like electronic component is locked, therebyprotecting the ejector from damage and failure.

Furthermore, even if an external force is applied to the card-likeelectronic component to remove it from the card insertion port, thecomponent is held in the card storage portion by the lock member.Therefore, the card-like electronic component can be prevented fromremoval from the card storage portion.

In order to achieve the fifth object, according to the presentinvention, there is provided a portable electronic apparatus comprisinga case having a bottom surface, an upper surface opposing the bottomsurface, and a peripheral surface continuous with the bottom surface andthe upper surface, the peripheral surface having an card insertion portformed therein, a circuit board housed in the case to be parallel to thebottom surface and the upper surface, the circuit board having upper andlower surfaces, and first and second card storage portions which arerespectively arranged on the upper and lower surfaces of the circuitboard and in which card-like electronic components are removably storedto be parallel to the circuit board, the first and second card storageportions being arranged at the same position to oppose each otherthrough the circuit board and respectively having opening portionsformed to oppose the card insertion port.

According to this arrangement, the first and second card storageportions are arranged in a stacked state in the direction of thicknessof the case. Card-like electronic components stored in the first andsecond card storage portions have very small thicknesses as comparedwith their widths. Even if, therefore, these components are stored inthe card storage portions, the overall thickness in the verticaldirection is small. For this reason, the space occupied by the cardstorage portions in the case is small, as compared with the case whereinthe two card storage portions are laterally arranged, thus realizing acompact case.

In addition, since the opening portions of the card storage portions arevertically arranged, the size of each card insertion port formed in theperipheral surface of the case can be reduced in the lateral direction.Therefore, the card insertion ports occupy a small proportion of theperipheral surface of the case, increasing the freedom in arrangingconnectors and switches on the peripheral surface.

In order to achieve the sixth object, according to the presentinvention, there is provided a portable electronic apparatus comprisinga case made of a synthetic resin material and having a leg mount portionon an upper surface thereof, the case having an inner surface coveredwith electromagnetic shield means, a circuit board which is housed inthe case and on which a circuit component which generates noise duringan operation is mounted, a display unit having a display and a legportion coupled to the leg mount portion, a conductive guide tubeextending between the leg mount portion and the leg portion, the guidetube having one end portion introduced into the case through the legmount portion, and the one end portion being electrically connected tothe electromagnetic shield means, and a cable for electricallyconnecting the display to the circuit board, the cable extending throughthe guide tube and being arranged between the case and the display unit.

According to this arrangement, since the cable for transmittingelectrical signals is covered with the guide tube at the portions wherethe cable extends between the leg portions and the leg mount portions,noise leaking from the cable can be shielded by the guide tube. Inaddition, since the guide tube is grounded to the case via theelectromagnetic shield means, leakage of noise from the spaces betweenthe leg portions and the leg mount portions can be prevented.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate a presently preferred embodimentof the invention, and together with the general description given aboveand the detailed description of the preferred embodiment given below,serve to explain the principles of the invention.

FIGS. 1A to 51 show a laptop computer according to an embodiment of thepresent invention, in which

FIG. 1A is a sectional view of the laptop computer;

FIG. 1B is an enlarged sectional view of a portion IA in FIG. 1A;

FIG. 1C is an enlarged sectional view of a portion IB in FIG. 1A;

FIG. 2 is a sectional view taken along a line II--II in FIG. 1A;

FIG. 3 is a perspective view of the computer in a state wherein adisplay unit is pivoted to an opening position;

FIG. 4 is a perspective view of the computer in a state wherein thedisplay unit is pivoted to the opening position, and a keyboard unit isremoved from a base unit;

FIG. 5 is a perspective view showing a state wherein the keyboard unitis removed from the base unit;

FIG. 6 is a perspective view of the keyboard unit;

FIG. 7 is a side view of the keyboard in a tilt-up state;

FIG. 8 is a left side view of the computer in a state wherein thedisplay unit is pivoted to the opening position;

FIG. 9 is a perspective view showing a state wherein the display unit ispivoted to a closing position to fold the computer into a box-likeshape;

FIG. 10 is a perspective view of the display unit in a state wherein afront panel is removed therefrom;

FIG. 11 is an enlarged perspective view of a portion XI in FIG. 10;

FIG. 12 is a sectional view showing a wiring portion of a cableextending between the base unit and the display unit;

FIG. 13 is a sectional view taken along a line XIII--XIII in FIG. 12;

FIG. 14A is a sectional view of a mount portion of a shield member;

FIG. 14B is a sectional view of the shield member;

FIG. 15 is a plan view of a connecting portion between the cable and aliquid crystal display in the display unit;

FIG. 16A is a sectional view of the display unit in a state wherein afront panel is to be stacked on a rear panel;

FIG. 16B is a sectional view showing a state wherein the front panel isstacked on the rear panel to assemble the housing of the display unit;

FIG. 17 is a plan view showing a connecting portion between the cableand a converter circuit in the display unit;

FIG. 18A is a sectional view of the display unit in a state wherein thefront panel is to be stacked on the rear panel;

FIG. 18B is a sectional view showing a state wherein the front panel isstacked on the rear panel to assemble the housing of the display unit;

FIG. 19 is a sectional view taken along a line XIX--XIX in FIG. 12;

FIG. 20 is an exploded perspective view of the computer in a statewherein a case body is removed from a bottom cover;

FIG. 21 is a perspective view of the computer in a state wherein a lowermount area is exposed;

FIG. 22 is a side view of a main circuit board;

FIG. 23 is an exploded perspective view showing the positionalrelationship between the main circuit board and a connector board;

FIG. 24 is a perspective view of the computer in a state wherein thebottom cover and the rear panel are removed from the case body;

FIG. 25 is a perspective view showing a mount portion of a cooling fan;

FIG. 26 is a perspective view of the computer in a state wherein aconnector cover is open;

FIG. 27 is a perspective view of the computer in a state wherein theconnector cover is kept closed;

FIG. 28 is a sectional view of the rear portion of the computer in astate wherein the connector cover is open;

FIG. 29 is a sectional view of the rear portion of the computer in astate wherein the connector cover is kept closed;

FIG. 30 is a rear view of the computer in a state wherein the rear panelis removed to expose the lower mount area;

FIG. 31 is a perspective view of a power supply unit;

FIG. 32 is a perspective view of the right rear end portion of thecomputer;

FIG. 33 is a sectional view of a card storage portion in the case;

FIG. 34A is a perspective view of the computer in a state wherein ashutter plate is opened to expose the card storage portion;

FIG. 34B is a side view of the computer in a state wherein the shutterplate is opened to expose the card storage portion;

FIG. 35A is a perspective view of the computer in a state wherein a lockplate is slid to a lock position;

FIG. 35B is a side view of the computer in a state wherein the lockplate is slid to the lock position;

FIG. 36 is a sectional view of a memory card mount portion in the case;

FIG. 37 is a side view of the memory card mount portion in the case;

FIG. 38 is a sectional view of a mount portion of a fan unit in thecase;

FIG. 39 is a sectional view of a mount portion of an expansion circuitboard in the case;

FIG. 40 is an exploded perspective view of an HDD assembly;

FIG. 41 is a sectional view of the HDD assembly;

FIG. 42 is a sectional view showing a state wherein the HDD assembly ismounted in the lower mount area in the case;

FIG. 43 is a plan view showing a state wherein the HDD assembly ismounted in the lower mount area in the case;

FIG. 44 is an exploded perspective view of a CD drive and a bracket;

FIG. 45 is a perspective view showing a state wherein the CD drive ismounted in the lower mount area in the case;

FIG. 46A is a sectional view showing a state wherein the CD drive ismounted in the lower mount area in the case;

FIG. 46B is a sectional view showing a state wherein an opening portionof the case is covered with a cover;

FIG. 47 is an exploded perspective view showing a state wherein aspeaker unit is removed from the case body;

FIG. 48 is a sectional view showing a state wherein the speaker unit ismounted on the case body;

FIG. 49 is an exploded perspective view of the speaker unit;

FIG. 50 is an exploded perspective view showing a state wherein anopening/closing cover is removed from a keyboard mount portion of thecase; and

FIG. 51 is a sectional view showing the positional relationship betweenthe opening/closing cover and the circuit board.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A laptop portable computer according to an embodiment of the presentinvention will be described below with reference to the accompanyingdrawings.

FIG. 3 shows the outer appearance of a portable computer 1. The portablecomputer 1 comprises a base unit 2 and a flat panel type display unit 3.

The base unit 2 has a box-like case 4. As shown in FIGS. 1A and 20, thecase 4 is divided into two parts, i.e., a case body 5 and a bottom cover6. The entire bottom and rear surfaces of the case body 5 are open. Therear surface is continuous with the bottom surface. The bottom cover 6covers the opening portion on the bottom surface of the case body 5. Thecase body 5 and the bottom cover 6 are made of a synthetic resinmaterial such as an ABS resin. The case 4 of this embodiment is coloredin a whitish color.

The case body 5 has a flat upper wall 5a, a front wall 5b, and left andright side walls 5c and 5d. The latter three walls are continuous withthe upper wall 5a. As shown in FIG. 4, a keyboard mount portion 7 isformed on the front half of the upper wall 5a. The keyboard mountportion 7 has a flat mount surface 7a which is lower in level than therear half of the upper wall 5a. The mount surface 7a is open andcontinuous with the front wall 5b and the left and right side walls 5cand 5d of the case body 5. Positioning projections 8a and 8b are formedupright on the left and right side portions of the front end of themount surface 7a.

As shown in FIG. 5, a cord guide 9 is mounted on the rear end portion ofthe keyboard mount portion 7. The cord guide 9 has an upper wall portion10 which is continuous with the rear half of the upper wall 5a on thesame plane. The upper wall portion 10 has a length equal to the totalwidth of the case body 5. Seat portions 11a and 11b are respectivelyformed on the left and right end portions of the upper wall portion 10.The seat portions 11a and 11b are fixed to the upper wall 5a via screws12 shown in FIG. 1A. The left and right side surfaces of the seatportions 11a and 11b are continuous with the left and right side walls5c and 5d of the case body 5 on the same plane.

A cord storage portion 13 is formed between the 10 upper wall portion 10of the cord guide 9 and the mount surface 7a. The cord storage portion13 is open to the keyboard mount portion 7. The left and right endportions of the cord storage portion 13 are closed by the seat portions11a and 11b. The left seat portion 11a has a groove-like cord extractionport 14 which is continuously formed in the front and side surfaces ofthe seat portion 11a. A cord engaging portion 15 is formed on the rightend portion of the cord storage portion 13. The cord engaging portion 15has a first projection 15a protruding downward from the upper wallportion 10, and a second projection 15b protruding upward from the mountsurface 7a. A space 15c is formed between the distal end portions of thefirst and second projections 15a and 15b. The space 15c is open to thecord storage portion 13 and the keyboard mount portion 7.

A keyboard unit 18 is detachably mounted on the keyboard mount portion7. The keyboard unit 18 has a rectangular keyboard case 19 and a largenumber of keys 20 incorporated in the keyboard case 19. When thekeyboard unit 18 is mounted on the mount surface 7a, the upper surfacesof the keyboard case 19 and the keys 20 are almost continuous with theupper wall 5a of the case body 5 on the same plane. The keyboard case 19has fitting holes 21a and 21b in the left and right side portionsthereof. These fitting holes 21a and 21b are opened in the upper andlower surfaces of the keyboard case 19.

With this structure, when the keyboard unit 18 is mounted at apredetermined position on the mount surface 7a, the projections 8a and8b are fitted in the fitting holes 21a and 21b. with this fittingoperation, the keyboard unit 18 is positioned in all directions withrespect to the mount surface 7a. The projections 8a and 8b are exposedon the upper surface of the keyboard unit 18 via the fitting holes 21aand 21b.

As shown in FIG. 5, the keyboard unit 18 is connected to the base unit 2via a cord 25. The cord 25 has an extendible curl portion 26. One end ofthe cord 25 is connected to the keyboard case 19, and the other end ofthe cord 25 is inserted into the base unit 2 via a cord introductionport 27 opened in the mount surface 7a.

As shown in FIG. 7, the keyboard unit 18 has a pair Of left and righttilt legs 28 (only one of them is shown in FIG. 7) at the rear endportion of the keyboard case 19. The tilt legs 28 serve to cause thekeyboard unit 18 to tilt up such that the front side becomes lower inlevel than the rear side, when the keyboard unit 18 is detached from thebase unit 2 and placed on, e.g., the surface of a desk. Each tilt leg 28is supported on the keyboard case 19 through a pivot shaft 29 to bepivotal between a storing position at which the leg is retracted intothe keyboard case 19 and a using position at which the leg protrudesdownward from the keyboard case 19. Rubber slip preventing members 30are attached to the distal ends of the tilt legs 28. The slip preventingmembers 30 serve to prevent the keyboard unit 18 from slipping when theunit 18 is placed on a flat desk surface and operated, thus improvingthe operability of the keyboard unit 18 together with theabove-mentioned tilt-up structure.

As shown in FIG. 6, the keyboard case 19 has a cord receiving portion32. The cord receiving portion 32 is formed in the left half of the rearend of the keyboard case 19. One end of the cord 25 is inserted in thecord receiving portion 32. The cord receiving portion 32 becomescontinuous with the cord storage portion 13 when the keyboard unit 18 ismounted on the keyboard mount portion 7.

When the keyboard unit 18 is to be mounted on the keyboard mount portion7, the cord 25 pulled out from the cord introduction port 27 is insertedinto the right side of the cord storage portion 13 and is reversed atthe right end portion of the cord storage portion 13, as shown in FIG.5. The reversed portion of the cord 25 is then pushed into the cordstorage portion 13 via the space 15c of the cord engaging portion 15 tolocate the curl portion 26 at the left side of the cord storage portion13. In this state, the keyboard unit 18 is mounted on the mount surface7a, and the curl portion 26 is stored in the space defined by the cordstorage portion 13 and the cord receiving portion 32.

When the keyboard unit 18 is to be detached from the keyboard mountportion 7 and used, the keyboard unit 18 is detached from the mountsurface 7a first, and the cord 25 is then pulled out from the cordstorage portion 13 onto the mount surface 7a via the space 15c of thecord engaging portion 15. In this state, the cord 25 is placed acrossthe mount surface 7a and hence becomes noticeable, which is undesirablein terms of the outer appearance. For this reason, as shown in FIG. 4,the cord 25 pulled out onto the mount surface 7a is introduced to theleft side of the mount surface 7a and is pushed into the left endportion of the cord storage portion 13 via the cord extraction port 14.Since the cord extraction port 14 is continuously formed in the leftside surface of the case body 5, the cord 25 pushed into the cordstorage portion 13 is introduced to the left side of the base unit 2without crossing the mount surface 7a. With this structure, in using thekeyboard unit 18 detached from the mount surface 7a, the cord 25 can beneatly placed without being noticeable by introducing the cord 25 to theleft side of the mount surface 7a and extracting it from the cordextraction port 14.

As described above, immediately after the cord 25 is pulled out from thecord introduction port 27, the cord 25 is pulled either to the left orthe right depending on the setting position of the keyboard unit 18. Forthis reason, in this embodiment, the diameter of the cord introductionport 27 is set to be much larger than that of the cord 25, and the innersurface of the cord introduction port 27 is inclined in the form of acone. According to this structure, the cord 25 is guided by the innersurface of the cord introduction port 27 to be smoothly bent. Therefore,no excessive force is applied to the cord 25 when the pulling directionof the cord 25 is changed.

As shown in FIG. 4, the upper wall 5a of the case body 5 has aprojection 35 on the rear end portion of the rear half thereof. Theprojection 35 extends along the widthwise direction of the case body 5.A pair of left and right leg mount portions 36a and 36b for coupling thedisplay unit 3 to the case body 5 are formed on the left and right sideportions of the projection 35. The entire inner surfaces of the casebody 5 including the projection 35 and the bottom cover 6 arerespectively covered with conductive layers 37a and 37b formed bydeposition of aluminum, as shown in FIGS. 1B and 1C. In this embodiment,the layers 37a and 37b constitute an electromagnetic shield means.

The display unit 3 comprises a box-like housing 40 consisting of asynthetic resin material, and a liquid crystal display 41 housed in thehousing 40. The housing 40 has a rear panel 43 and a front panel 42detachably coupled to the rear panel 43. As shown in FIG. 14, the innersurfaces of the front and rear panels 42 and 43 are respectively coveredwith conductive layers 42a and 43a formed by deposition of aluminum.

As shown in FIG. 10, the liquid crystal display 41 comprises a liquidcrystal panel 47 and a metal frame 48 enclosing the liquid crystal panel47. A driving circuit 49 for the liquid crystal display 41 is arrangedat the upper and lower portions and left side portion of the liquidcrystal panel 47. As shown in FIGS. 16A and 16B, the driving circuit 49has a circuit board 49b on which a large number of circuit components49a are mounted. The circuit board 49b is supported on the frame 48. Theframe 48 is fixed to the rear panel 43 with screws. By this fixingoperation using the screws, the liquid crystal panel 47 is exposed tothe outside of the housing 40 through a display window 50 formed in thefront panel 42.

A rib 44 is formed on the inner surface of the rear panel 43 to surroundthe liquid crystal display 41. As shown in FIGS. 16B and 18B, the distalend of the rib 44 is located near the inner surface of the front panel42 when the front panel 42 is coupled to the rear panel 43. As shown inFIG. 15, a first cable insertion path 45 is formed between the left endportion of the liquid crystal display 41 and the rib 44.

As shown in FIGS. 10 and 17, a converter circuit 52 of the liquidcrystal display 41 is supported on the inner surface of the rear panel43. The converter circuit 52 has a circuit board 52b on which a largenumber of circuit components 52a are mounted. This converter circuit 52is located on the right side of the liquid crystal display 41 and therib 44. A second cable insertion path 46 is formed between the left endportion of the converter circuit 52 and the rib 44. The convertercircuit 52 is electrically connected to the driving circuit 49 via alead wire 53.

The housing 40 has first and second leg portions 55 and 56. The firstand second leg portions 55 and 56 are spaced apart from each other inthe lateral direction of the housing 40. The leg portions 55 and 56 arerespectively coupled to the leg mount portions 36a and 36b of the casebody 5 via metal hinge members 57. Since the left and right metal hingemembers 57 are identical to each other, the left metal hinge member 57will be described as a representative.

As shown in FIG. 11, the metal hinge member 57 comprises a first bracket58 fixed to the leg mount portion 36a, a second bracket 59 fixed to theinner surface of the rear panel 43 including the first pivot leg portion55, and a hinge shaft 60 extending between the brackets 58 and 59. Thefirst and second brackets 58 and 59 and the hinge shaft 60 are made of aconductive metal material. The first bracket 58 is fixed to the casebody 5 via a metal screw 61 threadably engaged therewith from the insideof the case body 5. With this structure, the first bracket 58 iselectrically connected to the layer 37a of the case body 5 via the metalscrew 61. The second bracket 59 is fixed to the inner surface of therear panel 43 via a metal screw 62. The second bracket 59 is in contactwith the layer 43a covering the inner surface of the rear panel 43 to beelectrically connected to the layer 43a. The hinge shaft 60 extendsthrough the left side surface of the first leg portion 55. One end ofthe hinge shaft 60 is fixed to the second bracket 59, and the other endof the hinge shaft 60 is coupled to the first bracket 58 to be pivotalabout the axis. A large-diameter metal press ring 63 is fixed to theother end of the hinge shaft 60. A wave washer 64 is clamped between thepress ring 63 and the first bracket 58. The wave washer 64 provides africtional resistance between the first bracket 58 and the hinge shaft60. Owing to the presence of this frictional resistance, free pivotalmovement of the hinge shaft 60 is restrained.

With this structure, the display unit 3 is supported on the base unit 2to be pivotal between the first position at which the display unit 3covers the rear half of the case body 5 and the keyboard unit 18 fromabove and the second position at which an operator can operate the keys20 while watching the liquid crystal panel 47. As shown in FIG. 9, whenthe display unit 3 is pivoted to the first position, the housing 40 ofthe display unit 3 becomes continuous with the front, left, and rightsurfaces of the case body 5 and the upper surface of the projection 35on the same plane. Hence, the portable computer 1 becomes a portablebox-like unit as a whole.

As shown in FIG. 11, the metal hinge member 57 has a ground terminal 66.The ground terminal 66 has a pair of contact pieces 67 which are inslidable contact with the end face of the hinge shaft 60. The groundterminal 66 is clamped between the first bracket 58 and a press plate 68fixed to the first bracket 58 with screws. With this structure, theground terminal 66 is electrically connected to the layer 37a of thecase body 5 via the first bracket 58, and is also electrically connectedto the layer 43a of the display unit 3 via the second bracket 59. Withthis structure, the display unit 3 is grounded to the base unit 2 viathe metal hinge member 57.

The first bracket 58 and ground terminal 66 of the metal hinge member 57are covered with a hinge cover 69. The hinge cover 69 is detachablyengaged by lock pawls 70 extending vertically upward from the case body5 and the press plate 68. The first leg portion 55 is inserted betweenthe hinge cover 69 and the projection 35.

As shown in FIGS. 11 and 12, a cable insertion hole 73 is opened in theright side surface of the first leg portion 55. The right side surfaceof the first leg portion 55 opposes the left side surface of theprojection 35. The left side surface of the projection 35 is continuouswith the bottom surface of the leg mount portion 36a. A bottom opening74 communicating with the inside of the case body 5 is formed in thebottom surface of the leg mount portion 36a. A side opening 75communicating with the bottom opening 74 is formed in the left sidesurface of the projection 35.

A cover 76 consisting of a synthetic resin material is mounted on theleg mount portion 36a from the inside of the case body 5. The cover 76has a bottom wall covering the bottom opening 74 and a side wall 78covering the side opening 75. The side wall 78 has a support piece 79extending inside the projection 35. As shown in FIG. 13, the supportpiece 79 has a tongue piece 80, which is fixed to a seat portion 81 onthe inner surface of the projection 35 with a screw 82.

The upper edge portion of the side opening 75 and the upper edge portionof the side wall 78 constitute a cable path 85. The cable path 85communicates with the cable insertion hole 73. A cable 86 extendsthrough the cable path 85 and the cable insertion hole 73. The cable 86serves to electrically connect the liquid crystal display 41 of thedisplay unit 3 to the base unit 2. As shown in FIG. 13, the cable 86comprises a flexible outer tube 87 and a plurality of lead wires 88extending through the outer tube 87. One end of the cable 86 is insertedinto the first cable insertion path 45 in the housing 40 from the insideof the first leg portion 55. In addition, the other end of the cable 86is inserted into the case body 5 via the inside of the projection 35.

As shown in FIG. 15, the lead wires 88 of the cable 86 are introducedfrom the outer tube 87 in the first cable insertion path 45. Theextracted portions of the lead wires 88 are grouped into four bundles88a, 88b, 88c, and 88d. The bundles 88a, 88b, 88c, and 88d respectivelyhave connectors 89a, 89b, 89c, and 89d at their distal ends. Theconnectors 89a, 89b, and 89c of the three bundles 88a, 88b, and 88c, ofthe four bundles 88a to 88d, are connected to the circuit board 49b ofthe driving circuit 49. As shown in FIG. 19, the remaining bundle 88d isguided to the right side of the liquid crystal display 41 via a space 94between the rib 44 and the lower end portion of the liquid crystaldisplay 41. The distal end of the bundle 88d is introduced to the secondcable insertion path 46 together with the connector 86d, which isconnected to the circuit board 52b of the converter circuit 52. Withthis structure, the bundle 88d of the lead wires 88 is arranged in thehousing 40 from the left to the right without passing between the liquidcrystal display 41 and the rear panel 43, thereby allowing the operatorto easily check the wiring position of the bundle 88d.

As shown in FIGS. 16A and 16B, a transparent insulator 84 consisting ofa synthetic resin material is bonded to the rib 44. The insulator 84 hasa plate-like spacer piece 84a inserted between the first cable insertionpath 45 and the front panel 42. The spacer piece 84a holds the bundles88a, 88b, and 88c of the lead wires 88 inside the first cable insertionpath 45 to prevent the bundles 88a to 88c from being caught between thefront panel 42 and the rib 44 when the front panel 42 is placed on therear panel 43, as shown in FIG. 16A.

As shown in FIGS. 17, 18A, and 18B, the converter circuit 52 has a cover54 for covering the circuit components 52a and the circuit board 52b.The cover 54 is made of a transparent synthetic resin material. Thecover 54 has a plate-like spacer piece 54a partly protruding inside thesecond cable insertion path 46. The spacer piece 54a holds the bundle88d of the lead wires 88 inside the second cable insertion path 46 toprevent the bundle 88d from being caught between the front panel 42 andthe rib 44 when the front panel 42 is placed on the rear panel 43, asshown in FIG. 18A.

As shown in FIGS. 11 to 13, a metal guide tube 90 extends through thecable insertion hole 73 and the cable path 85. The guide tube 90 has acylindrical shape and is coaxially arranged with the hinge shaft 60 ofthe metal hinge member 57. One end of the guide tube 90 is inserted inthe first leg portion 55, and the other end of the guide tube 90 isinserted inside the projection 35. The cable 86 extends through theguide tube 90. A support piece 91 is integrally formed on the other endof the guide tube 90. The support piece 91 is clamped between the tonguepiece 80 and the seat portion 81 inside the projection 35. In this case,since the seat portion 81 is covered with the conductive layer 37, theguide tube 90 is electrically connected to the layer 37 via the supportpiece 91.

As shown in FIGS. 12 and 14A, a shield member 92 is bonded to the innersurface of the first leg portion 55. As shown in FIG. 14B, the shieldmember 92 comprises an outer tube 92a formed by plating the surface of apolyester fiber with a conductive metal, and a foamed urethane elasticmember 92b filling the outer tube 92a. The shield member 92 is bentalong the outer surface of the guide tube 90 and is in slidable contacttherewith. Since the inner surface of the first leg portion 55 iscovered with the layer 43a, the guide tube 90 is electrically connectedto the layer 43a via the shield member 92.

As shown in FIG. 3, the display unit 3 has a pair of left and rightlatch pawls 93a and 93b on the upper portion of the front surface of thehousing 40. When the display unit 3 is pivoted to the first position,the latch pawls 93a and 93b are engaged in the projections 8a and 8bexposed on the upper surface of the keyboard unit 18 to be freelydisengaged therefrom. With this engaging operation, the display unit 3is located at the first position, and the keyboard unit 18 is heldbetween the display unit 3 and the mount surface 7a of the base unit 2so as not be fall off.

As shown in FIG. 9, the case 4 has a carrying handle 95 at the centralportion of the front wall 5b. The handle 95 comprises a pair of legportions 95a and 95b pivotally coupled to the front wall 5b via a metalhinge member 99 (shown in FIG. 43), and a grip portion 95c extendingbetween the leg portions 95a and 95b. The front wall 5b is continuouswith the front end portion of the bottom cover 6. A handle receivingportion 96 is formed on the front end portion of the bottom cover 6. Thehandle receiving portion 96 has a first recess 96a in which the gripportion 95c of the handle 95 can be retracted. The front wall 5b hassecond and third recesses 97a and 97b in which the leg portions 95a and95b of the handle 95 can be retracted. The second and third recesses 97aand 97b are continuous with the two ends of the first recess 96a.

With this structure, the handle 95 is held on the case 4 to be pivotalbetween a using operation at which the handle 95 protrudes from the case4, as shown in FIG. 9, and a storing position at which the handle 95 isretracted in the first to third recesses 96a, 97a, and 97b, as shown inFIG. 3. When the handle 95 is pivoted to the storing position, the legportions 95a and 95b and the grip portion 95c become continuous with thefront wall 5b on the same plane.

Note that a push latch unit 98 locked in the grip portion 95c to befreely disengaged therefrom is mounted in the first recess 96a. Thehandle 95 is held at the storing position by the latch unit 98.

As shown in FIGS. 1A and 2, a main circuit board 100 is housed in thecase 4. The main circuit board 100 has substantially the same size asthat of the bottom cover 6. A plurality of portions of the peripheraland central portions of the main circuit board 100 are supported on theupper wall 5a of the case body 5. This support structure will be furtherdescribed below. As shown in FIG. 1A, a plurality of columnar bossportions 101 are integrally formed on the inner surface of the upperwall 5a to extend downward. The lower end faces of the boss portions 101are located on the same plane and at a substantially intermediateposition of the case 4 in the direction of thickness. The main circuitboard 100 is stacked on the lower end faces of the boss portions 101 andis fastened and fixed thereto with metal screws 102. With thisstructure, the interior of the case 4 is partitioned into an upper mountarea 103 and a lower mount area 104 by the main circuit board 100.

As shown in FIGS. 1A and 20, the bottom cover 6 as the bottom of thelower mount area 104 integrally has a plurality of hollow cylindricalmount seat portions 105. The mount seat portions 105 extend upward froma plurality of portions of the peripheral portion of the bottom cover 6and from its central portion. These mount seat portions 105 are open tothe bottom surface of the bottom cover 6. A plurality of columnarcoupling seat portions 106 are integrally formed upright on the innersurface of the upper wall 5a. The coupling seat portions 106 extenddownward from the upper wall 5a. The lower end faces of the couplingseat portions 106 are abutted against the upper end faces of the mountseat portions 105. The bottom cover 6 is detachably coupled to the casebody 5 by threadably engaging screws 107, which are inserted from theopening ends of the mount seat portions 105, with the coupling seatportions 106. When the bottom cover 6 is detached from the case body 5upon loosening the screws 107, the entire lower mount area 104 is opento the outside of the case 4.

The main circuit board 100 has an upper surface opposing the upper mountarea 103 and a lower surface opposing the lower mount area 104. As shownin FIG. 22, various types of circuit components 108 such as IC chips andresistors are mounted on the upper and lower surfaces of the maincircuit board 100. These circuit components 108 include parts whichgenerate high-frequency noise while they are in operation. A main CPU109 is mounted on the upper surface of the main circuit board 100 to beadjacent to the circuit components 108. This CPU 109 has a large numberof cooling fins 110 because it generate a large amount of heat. Of thecircuit components 108, large and tall parts such as IC chips andcondensers are mounted on the upper surface of the main circuit board100 and arranged in the upper mount area 103. In contrast to this, smallcircuit components 108 such as resistors are mounted on the lowersurface of the main circuit board 100 and arranged in the lower mountarea 104. With this structure, the lower surface, of the main circuitboard 100, which opposes the lower mount area 104 is kept flat withsmall unevenness even in a state wherein the circuit components 108 aremounted thereon. The lead wires 88 are connected to the rear end portionof the upper surface of the main circuit board 100.

As shown in FIGS. 1A and 23, a connector board 115 is arranged at therear end portion of the main circuit board 100. The connector board 115is arranged independently of the main circuit board 100 and positionedat a right angle with respect to the main circuit board 100. The maincircuit board 100 and the connector board 115 are electrically andmechanically connected to each other via connectors 116a and 116b. Theconnector board 115 is located at the rear end portion of the uppermount area 103 to oppose the opening portion of the rear surface of thecase body 5.

As shown FIGS. 24 and 28, a plurality of expansion connectors 117 forconnection of peripheral devices such as an external CRT, a printer, anda large-capacity floppy disk drive are mounted on the rear surface ofthe connector board 115. The expansion connectors 117 are located abovethe upper surface of the main circuit board 100, so that parts arethree-dimensionally arranged at the rear portion of the main circuitboard 100. With this structure, the main circuit board 100 need not havea space for mounting the expansion connectors 117, thereby achieving areduction in the size of the main circuit board 100. In addition, partscan be easily arranged on the main circuit board 100 in terms of thespace.

A rear shield plate 118 consisting of a metal is supported on the rearend portion of the main circuit board 100. The rear shield plate 118 isparallel to the connector board 115 and covers the connecting portionbetween the connector board 115 and the expansion connectors 117 and theupper mount area 103 from behind. The rear shield plate 118 has upperand lower flange portions 119 and 120 at its upper and lower edges,respectively. The upper flange portion 119 is in contact with the layer37a of the case body 5 at the upper edge of the opening of the rearsurface of the case body 5. As shown in FIGS. 23 and 30, a plurality ofcommunicating holes 138 communicating with the upper mount area 103 areopened in the right end portion of the rear shield plate 118.

As shown in FIG. 27, a rear panel 123 consisting of a synthetic resinmaterial is detachably mounted on the case body 5 with screws 124 so asto cover the rear opening portion. A rectangular recess 125 is formed inthe central portion of the rear panel 123. A connector exposure port 126for exposing the expansion connectors 117 is formed in the upper half ofthe recess 125. A connector cover 127 consisting of a synthetic resinmaterial is supported on the recess 125. The connector cover 127 servesto open/close the connector exposure port 126.

As shown in FIGS. 28 and 29, the connector cover 127 has shaft portions128 on its left and right end portions. The shaft portions 128 arepivotally supported on the left and right side surfaces of the recess125. With this structure, the connector cover 127 is supported on therear panel 123 to be pivotal between a closing position at which theconnector exposure port 126 is closed, as shown in FIGS. 27 and 29, andan opening position at which the connector exposure port 126 is openedto expose the expansion connectors 117, as shown in FIGS. 26 and 28.When the connector cover 127 is pivoted to the closing position, theconnector cover 127 becomes continuous with the rear panel 123 on thesame plane to constitute part of the rear panel 123. When the connectorcover 127 is pivoted to the opening position, the connector cover 127enters the lower half of the recess 125 to prevent a deterioration inintegrity with the rear panel 123.

The rear panel 123 has an upper vent 131 communicating with the uppermount area 103, and a lower vent 132 continuous with the lower mountarea 104. The vents 131 and 132 are constituted by a large number ofsmall holes arranged in the form of a mesh. As shown in FIGS. 26 and 27,the upper vent 131 is arranged on the right side of the recess 125 tocommunicate with the communicating holes 138 of the rear shield plate118, when viewed from the rear side of the portable computer 1. Thelower vent 132 is arranged on the left side of the recess 125 and theleft side of the lower half of the recess 125. A communicating hole 133is formed in the left half of the connector cover 127. The communicatinghole 133 is constituted by a large number of small holes arranged in theform of a mesh. As shown in FIG. 28, when the connector cover 127 ispivoted to the opening position, the communicating hole 133 communicateswith the lower vent 132. With this structure, even in the open state ofthe connector cover 127, the lower vent 132 is not closed by the lowervent 132.

As shown in FIGS. 28 and 29, a metal reinforcing plate 135 is stacked onthe inner surface of the rear panel 123. The reinforcing plate 135serves to prevent the rear panel 123 from being deformed or damaged whenthe case 4 is pressed vertically. With the reinforcing plate 135, therigidity of the case 4 is increased. As shown in FIGS. 20 and 28, thereinforcing plate 135 has a notched portion 136 bypassing the connectorexposure port 126, and a plurality of communicating holes 137communicating with the upper vent 131 and the lower vent 132. Thereinforcing plate 135 is stacked on the rear shield plate 118 and isfixed to the case body 5 with the screws 124 together with the rearshield plate 118 and the rear panel 123. A flange portion 135a is formedon the lower end portion of the reinforcing plate 135. when the rearpanel 123 is fixed to the case body 5, the flange portion 135a isbrought into contact with the layer 37b covering the inner surface ofthe bottom cover 6. With this structure, the reinforcing plate 135 andthe case 4 are electrically connected to each other.

As shown in FIG. 1A, a floppy disk drive (to be referred to as an FDDhereinafter) 140 and a power supply unit 150 as standard units arearranged in the upper mount area 103 to be adjacent to each other in theback-and-forth direction. The FDD 140 is located below the keyboardmount portion 7. The FDD 140 has a metal casing 141. An insertion port142 and a push button 143 are arranged on the front surface of thecasing 141. The insertion port 142 allows a floppy disk to beloaded/unloaded therethrough. The push button 143 is depressed to ejectan inserted floppy disk. A bracket 144 is mounted on the casing 141.This bracket 144 has tongue pieces 144a and 144b extending from the twosides of the casing 141. The FDD 140 is stacked on the inner surface ofthe mount surface 7a. The tongue pieces 144a and 144b of the bracket 144are fixed to boss portions 145 on the inner surface of the mount surface7a with screws. With this structure, the FDD 140 is suspended from themount surface 7a, and the insertion port 142 and the push button 143 areexposed on the right side wall 5d of the case body 5.

As shown in FIG. 1A, the power supply unit 150 is disposed in the rearhalf of the upper mount area 103. As shown in FIG. 31, the power supplyunit 150 has a metal case 153. This case 153 has a box-like shapeextending in the lateral direction of the case 4. A plurality of fixingtongue pieces 154 are integrally formed on the peripheral portion of thecase 153. As shown in FIGS. 1A and 2, a power supply board 152 is housedin the case 153. Various circuit components 151 constituting a powersupply circuit are mounted on the power supply board 152.

A power switch 155, a power supply connector 156, and a first coolingfan 157 are incorporated in the case 153. The power supply connector 156allows connection of an external power supply. The first cooling fan 157serves to draw heat from the case 153. The power switch 155 and thefirst cooling fan 157 are arranged on the right side surface of thepower supply unit 150 to be adjacent to each other in the back-and-forthdirection. The power supply connector 156 is disposed on the right endportion of the rear surface of the power supply unit 150. A plurality ofinlet holes 158 communicating with the inside and outside of the case153 are formed in the left end portion of the rear surface of the case153. Note that FIG. 2 is a perspective view of the portable computer 1when viewed from behind, and the positions of the power switch 155, thepower supply connector 156, and the like are laterally reversed to thosedescribed above.

The power supply unit 150 is stacked on the inner surface of the upperwall 5a in a posture in which the power switch 155 and the first coolingfan 157 face the right side of the case body 5, and the power supplyconnector 156 faces the rear surface side of the case body 5. The tonguepieces 154 of the power supply unit 150 are fixed to boss portions 159extending from the inner surface of the upper wall 5a with screws. Withthis structure, the power supply unit 150 is suspended from the innersurface of the upper wall 5a, and the lower surface of the case 153 isdisposed near the main circuit board 100.

As shown in FIG. 2, the inner surface of the rear portion of the rightside wall 5d of the case body 5 is located near the right side surfaceof the power supply unit 150. As shown in FIGS. 26 and 27, an exposureport 162 and an exhaust port 163 are formed in the rear portion of theright side wall 5d. The exposure port 162 serves to expose the powerswitch 155. The exhaust port 163 opposes the first cooling fan 157. Theexhaust port 163 is constituted by a large number of small holesarranged in the form of a mesh. With this structure, when the firstcooling fan 157 is operated, outer air is drawn into the rear portion ofthe upper mount area 103 via the upper vent 131 of the case body 5. Theair is then introduced from the rear portion into the case 153 via theinlet holes 158. The outer air introduced into the case 153 flows aroundthe circuit components 151 which generate heat, thus cooling the circuitcomponents 151 and the power supply board 152. The outer air is directlyexhausted outside the case 4 via the exhaust port 163.

As shown in FIGS. 2 and 33, a card storage portion 171 in which a cardmodem 170 is mounted is disposed on the upper surface of the maincircuit board 100. The card storage portion 171 is positioned at theleft end portion of the rear half of the upper mount area 103 to bedisposed on the left side of the power supply unit 150. As shown inFIGS. 33, 34A, 34B, 35A, and 35B, the card storage portion 171 has apair of guide rails 172a and 172b for guiding insertion of the cardmodem 170, and a card connector 173 located at the distal end portionsof the guide rails 172a and 172b. The distal end portions, of the guiderails 172a and 172b, located on the opposite side to the card connector173 protrude more to the left side than a side edge portion of the maincircuit board 100. A metal shield plate 174 extends between the distalend portions of the guide rails 172a and 172b. The card connector 173has a large number of pin terminals 173a. A terminal portion 175 on thelead leading end (in the inserting direction) of the card modem 170 isdetachably fitted/connected in/to the card connector 173. A cable 176for allowing connection of an external unit extends from the trailingend of the card modem 170.

The card storage portion 171 further includes an ejector 178 forejecting the inserted card modem 170. The ejector 178 has the samearrangement as that of a known ejector. The ejector 178 has a push lever179 for pushing the leading end face of the card modem 170 in adirection to separate it from the card connector 173. The push lever 179is located adjacent to the guide rail portion 172b.

As shown in FIG. 33, a partition wall 180 protruding downward from theinner surface of the rear half of the upper wall 5a to oppose the cardstorage portion 171. The lower end of the partition wall 180 is incontact with the upper surfaces of the guide rails 172a and 172b and thecard connector 173 to partition the card storage portion 171 from theupper mount area 103.

The card storage portion 171 having the above structure is locatedadjacent to the inner surface of the left side wall 5c of the case body5. The left side wall 5c has a card insertion port 182 communicatingwith the card storage portion 171. The card insertion port 182 has arectangular shape extending in the back-and-forth direction. The distalend portions of the guide rails 172a and 172b and the push lever 179 areexposed through the card insertion port 182. Card modems 170 vary inthickness depending on the types. The thickness of card modems 170differs in accordance with the types of card modems 170. The differenceof the thickness between the thickest card modem 170 and the thinnestmodem 170 reaches several mm. For this reason, the height of the cardinsertion port 182 is set to allow insertion of the thickest card modem170.

A shutter plate 183 for opening/closing the card insertion port 182 issupported on the left side wall 5c of the case body 5. The shutter plate183 has a rectangular shape conforming to the shape of the cardinsertion port 182, and is placed along the inner surface of the leftside wall 5c. The shutter plate 183 is designed to slide between aclosing position at which the plate closes the card insertion port 182and an opening position at which the plate is pushed above the cardinsertion port 182 to open it.

The shutter plate 183 can be stopped at a position corresponding to thethickness of the card modem 170 when the card modem 170 is mounted inthe card storage portion 171. More specifically, as shown in FIG. 33, abraking member 184 consisting of a synthetic resin material is fixed tothe inner surface of the upper wall 5a with screws. The braking member184 has an elastic press piece 185. The press piece 185 extends downwardfrom the upper wall 5a and has an engaging projection 185a on its distalend. The engaging projection 185a is in slidable contact with the innersurface of the shutter plate 183. With this structure, the shutter plate183 is clamped between the left side wall 5c and the press piece 185 tobe vertically slidable, and is held at an arbitrary position between theopening position and the closing position by a frictional forcegenerated between the left side wall 5c and the press piece 185. Arecess 183a is formed in the lower end portion of the inner surface ofthe shutter plate 183. When the shutter plate 183 is slid to the openingposition, the engaging projection 185a is detachably engaged with therecess 183a.

With this structure, when a thin card modem 170 is loaded in the cardstorage portion 171, the card insertion port 182, which has a largeopening area compared with the thickness of the card modem 170, can beclosed to the minimum necessary height by lowering the shutter plate 183to the position of the card modem 170 and allowing only the cable 176 toextend from the card insertion port 182. Therefore, entrance of dust andforeign substances into the card storage portion 171 can be prevented,and the portable computer 1 can be maintained in a good state in termsof the outer appearance while the card modem 170 is used.

A lock mechanism 188 for preventing removal of the card modem 170 isarranged in the card storage portion 171. The lock mechanism 188 has ametal lock plate 189. The lock plate 189 is designed to be verticallyslidable between a lock position at which the plate enters the cardinsertion port 182 to cover the push lever 179 and a storing position atwhich the plate is retreated below the push lever 179. The lock plate189 has a knob 190 to be operated by a finger of the operator. The knob190 is exposed on the left side wall 5c of the case body 5. When theknob 190 is pressed vertically by a finger of the operator, the lockplate 189 is slid to the storing position or the lock position.

As shown in FIG. 35B, the lock plate 189 has a width larger than that ofthe push lever 179, and has a lock portion 189a protruding between theguide rails 172a and 172b. The lock portion 189a is hooked to thetrailing end of the card modem 170 loaded into the card storage portion171 when the lock plate 189 is pushed up to the lock position.

According to this lock mechanism 188, when the lock plate 189 is pushedup to the lock position after the card modem 170 is mounted in the cardstorage portion 171, the push lever 179 is covered with the lock plate189 and hence cannot be depressed while the card modem 170 is used. Thisprevents the operator from erroneously ejecting the card modem 170 fromthe card storage portion 171 while the card modem 170 is used.

According to the above description, while the card modem 170 is used,the lock portion 189a of the lock plate 189 is hooked to the trailingend of the card modem 170. For this reason, removal of the card modem170 from the card storage portion 171 can be prevented even if anexternal force is applied to the card modem 170 to extract it from thecard storage portion 171 when, for example, the cable 176 extending fromthe card insertion port 182 is pulled.

Since the lock plate 189 is hooked to the trailing end of the card modem170 at the same time the plate covers the push lever 179, the operatorcannot depress the push lever 179 with his/her finger while removal ofthe card modem 170 is prevented. If the card storage portion 171 isdesigned such that the card modem 170 is locked therein by only pushingthe trailing end of the card modem 170, the operator may forget to lockthe card modem 170, and depress the push lever 179. In this case, anundesirable force acts on a portion, of the ejector 178, which depressesthe card modem 170. As a result, the ejector 178 may be damaged.

In contrast to this, according to the lock mechanism 188 having theabove-described arrangement, when the lock plate 189 is pushed up to thelock position, the push lever 179 is covered with the lock plate 189 andhence cannot be accidentally depressed. This prevents the ejector 178from being damaged when the push lever 179 is erroneously operated.

As shown in FIGS. 22 and 36, first and second card storage portions 195aand 196a are provided inside the case 4. Each of the first and secondcard storage portions 195a and 196a removably houses the memory cards193 and 194 as card-like electronic components. The first card storageportion 195a is disposed on the upper surface of the main circuit board100. The second card storage portion 196a is disposed on the lowersurface of the main circuit board 100. Therefore, the first and secondcard storage portions 195a and 196a are provided at the same position soas to oppose each other across the main circuit board 100.

The first and second card storage portions 195a and 196a have a pair ofcard connectors 195 and 196 to which the memory cards 193 and 194 aredetachably connected. The card connectors 195 and 196 are located on theleft end portion of the front half of the main circuit board 100. Thecard connectors 195 and 196 are respectively disposed on the upper andlower surfaces of the main circuit board 100 at the same position so asto oppose each other through the main circuit board 100. The cardconnectors 195 and 196 have many pin terminals 197, respectively. Thepin terminals 197 to the card connectors 195 and 196 detachablyconnected to the terminal portions of the memory cards 193 and 194.

As shown in FIG. 36, the first and second card storage portions 195a and196a have metal housings 198 and 199. The metal housings 198 and 199 aredisposed on the upper and lower surfaces of the main circuit board 100,and cover the card connectors 195 and 196, respectively. The housings198 and 199 respectively have opening portions 198a and 199a on theirend portions on the opposite side to the pin terminals 197. The openingportions 198a and 199a respectively allow the memory cards 193 and 194to be inserted/removed therein/therefrom. Guide paths 200 and 201 forrespectively guiding the memory cards 193 and 194 to the card connectors195 and 196 are formed between the housings 198 and 199 and the maincircuit board 100. The guide paths 200 and 201 communicate with theopening portions 198a and 199a, respectively. The opening portions 198aand 199a are located near the inner surface of the left side wall 5c ofthe case body 5.

As shown in FIGS. 36 and 37, a card insertion port 203 is formed in thefront half of the left side wall 5c of the case body 5 so as to opposethe opening portions 198a and 199a. The card insertion port 203 has arectangular shape extending in the lateral direction. An inner cover 204is disposed between the card insertion port 203 and the opening portions198a and 199a of the guide paths 200 and 201. The inner cover 204 has aperipheral wall 205 extending along the edge portion of the cardinsertion port 203, and an end wall 206 continuous with the peripheralwall 205. The inner cover 204 is fixed to the inner wall of the casebody 5 with screws. The peripheral wall 205 covers the space between theleft side wall 5c and the main circuit board 100. The end wall 206 islocated between the guide paths 200 and 201 and the card insertion port203. An introduction port 207 communicating with the opening portions198a and 199a is opened in the end wall 206.

A card cover 208 for opening/closing the card insertion port 203 issupported on the left side wall 5c of the case body 5. The card cover208 has a plate-like rectangular shape conforming to the shape of thecard insertion port 203. The card cover 208 is disposed along the innersurface of the left side wall 5c and is designed to be verticallyslidable between a closing position at which the cover closes the cardinsertion port 203 and an opening position at which the cover is pushedbelow the card insertion port 203 to open the card insertion port 203.As shown in FIG. 36, while the memory cards 193 and 194 are connected tothe card connectors 195 and 196, the memory cards 193 and 194 arelocated deeper in the case 4 than the card insertion port 203. With thisstructure, the card cover 208 can be slid to the closing position toclose the card insertion port 203 regardless of the presence/absence ofthe memory cards 193 and 194.

As shown in FIGS. 21 and 32, the card insertion ports 182 and 203 areformed in the left side wall 5c of the case body 5 to be spaced apartfrom each other in the back-and-forth direction. An exhaust port 210 forcausing the inside and outside of the case 4 to communicate with eachother is formed between the card insertion ports 182 and 203. Theexhaust port 210 is constituted by a large number of small holesarranged in the form of a mesh. As shown in FIG. 38, the exhaust port210 communicates with both the upper mount area 103 and the lower mountarea 104. The CPU 109 which generates a large amount of heat is disposednear the exhaust port 210. As shown in FIGS. 4 and 5, a vent 211communicating with the upper mount area 103 is formed in the right sidewall 5d of the case body 5. This vent 211 is also constituted by a largenumber of small holes arranged in the form of a mesh, and is located onthe opposite side to the exhaust port 210.

As shown in FIGS. 1A and 2, the lower surface of the main circuit board100 which faces the lower mount area 104 is covered with a main shieldplate 215 consisting of a metal. The main shield plate 215 hassubstantially the same size as that of the main circuit board 100. Aplurality of mount pieces 216 bent upward are formed on the peripheralportion of the main shield plate 215. The main shield plate 215 is fixedto the case body 5 in such a manner that the mount pieces 216 arestacked on the lower surface of the main circuit board 100 and are fixedto the boss portions 101 with screws together with the main circuitboard 100. In this case, the main circuit board 100 has ground wiringpatterns 100a (shown in FIG. 39) at its portions in contact with themount pieces 216 and the boss portions 101. With this structure, whenthe main circuit board 100 and the main shield plate 215 are fixed tothe boss portions 101 with screws, the wiring patterns 100a are broughtinto contact with the layer 37a of the case body 5 and the main shieldplate 215 so as to electrically connect the main circuit board 100 andthe main shield plate 215 to the case body 5. As shown in FIGS. 28 and29, the rear end portion of the main shield plate 215 is stacked on thelower flange portion 120 of the rear shield plate 118 so that the mainshield plate 215 is also electrically connected to the rear shield plate118.

That is, the main shield plate 215 surrounds the upper mount area 103together with the layer 37a on the inner surface of the case body 5 andthe rear shield plate 118 to provide an electromagnetic shield, whichprevents high-frequency noise generated by the circuit components 108and noise from the FDD 140 and the power supply unit 150 from leakingoutside the case 4.

As shown in FIGS. 1A and 24, the lower mount area 104 is partitionedinto a first half zone 221 and a second half zone 222 by an expansioncircuit board 220. The expansion circuit board 220 is disposed at aright angle with respect to the main circuit board 100. The expansioncircuit board 220 is electrically connected to the lower surface of themain circuit board 100 via a connector 223. For this purpose, the mainshield plate 215 has an elongated opening portion 224 for allowing theconnector 223 to pass therethrough. As shown in FIG. 39, a reinforcingplate 225 is fixed to the front surface of the expansion circuit board220 which opposes the first half zone 221. The reinforcing plate 225also serves as a shield plate and has contact pieces 226 in contact withthe ground wiring patterns 100a of the main circuit board 100. Aplurality of expansion connectors 227a and 227b and a plurality of relayconnectors 228a and 228b are mounted on the rear surface of theexpansion circuit board 220 which opposes the second half zone 222.

As shown in FIG. 20, a hard disk drive (to be referred to as an HDDhereinafter) 231 and a bracket 232 for mounting a CD drive 230 using acompact disk (CD) as a ROM are detachably mounted on the first half zone221 of the lower mount area 104. FIG. 20 is a perspective view of thereversed portable computer 1, viewed from the bottom side of the case 4.The HDD 231 and the bracket 232 are located side by side.

As shown in FIG. 40, the HDD 231 comprises a housing having a hermeticstructure and a circuit board 235. A magnetic disk and a head are housedin the housing 233. The circuit board 235 is mounted on the lowersurface of the housing 233 via a board bracket 234. Flat signal cables237 are connected to the front end portion of the circuit board 235 viaa first connector 236, and power cables 239 are also connected to thefront end portion of the circuit board 235 via a second connector 238.FIG. 40 is a perspective view of the HDD 231, viewed from the lowersurface side. In FIG. 40, the posture of the HDD 231 is reversed withrespect to the case body 5.

The HDD 231 is supported on the lower surface of the main circuit board100 via an HDD bracket 241. The HDD bracket 241 comprises a bottom plate242 and a pair of side plates 243a and 243b. The bottom plate 242 coversthe circuit board 235 of the HDD 231 from below. The side plates 243aand 243b cover the HDD 231 from the left and right sides. Each of theside plates 243a and 243b has three support pieces 244a, 244b, and 244c.The left and right side surfaces of the board bracket 234 are clampedbetween the support pieces 244a, 244b, and 244c of the side plates 243aand 243b. One or a plurality of through holes 246 are formed in each ofthe support pieces 244a, 244b, and 244c. A mount screw 245 is to bethreadably engaged with each through hole 246. Each through hole 246matches one of a plurality of screw holes 247 formed in the left andright side surfaces of the board bracket 234. The HDD 231 is fixed tothe HDD bracket 241 by aligning the screw holes 247 with the throughholes 246 of the HDD bracket 241 and turning the screws 245 into thescrew holes 247 through the through holes 246. With this structure, thesignal cables 237 and the power cables 239 are arranged between thecircuit board 235 and the bottom plate 242 of the HDD bracket 241. Thesignal cables 237 and the power cables 239 are folded backwardimmediately after they are extracted from the first and secondconnectors 236 and 238, and the distal ends of these cables 237 and 239are detachably connected to the relay connector 228b of the expansioncircuit board 220 and a power supply connector (not shown) via aconnector 251.

As shown in FIGS. 40 and 41, the signal and power cables 237 and 239 arecovered with a cable guide 252. The cable guide 252 is formed by bendinga thin plate consisting of a hard synthetic resin material, and hasclamping portions 252a and 252b for vertically clamping the cables 237and 239. The cable guide 252 is inserted between the bottom plate 242 ofthe HDD bracket 241 and the circuit board 235. The clamping portion 252alocated above the cables 237 and 239 has first and second connectorcover portions 252c and 252d extending below the first and secondconnectors 236 and 238. The first and second connector cover portions252c and 252d protrude farther to the front wall 5b of the case body 5than the HDD bracket 241.

The HDD bracket 241 can also be applied to another large-capacity HDD asan optional unit. In this case, after the HDD 231 as a standard unit isdisconnected, an HDD as an optional unit may be inserted between theside plates 243a and 243b of the HDD bracket 241 to be fixed theretowith the screw holes of the HDD being aligned with the through holes246.

As shown in FIG. 42, the side plates 243a and 243b of the HDD bracket241 have a plurality of support pieces 250 to be stacked on the mountpieces 216 of the main shield plate 215. The support pieces 250 arefixed to the boss portions 101 together with the main circuit board 100and the main shield plate 215 by using the screws 102. With thisstructure, the HDD 231 is supported on the case body 5. The HDD 231 isdisposed in a posture in which the first and second connectors 236 and238 face the front wall 5b of the case body 5. The second connector 238protrudes farther forward than the housing 233 and the HDD bracket 241,and is located near the handle receiving portion 96 of the bottom cover6. For this reason, in this embodiment, a first guide piece 252e forrestraining the power cables 239 from protruding forward is integrallyformed on the first connector cover portion 252c of the cable guide 252.As shown in FIGS. 42 and 43, the first guide piece 252e extends upwardfrom the connector cover portion 252c. The upper end of the first guidepiece 252e reaches the inside of the second recess 97a of the case body5 and is located inside the fitting portion between the second recess97a and the handle receiving portion 96 of the bottom cover 6. Thefolded portions of the power cables 239 are abutted against the innersurface of the first guide piece 252e to restrain the power cables 239from protruding forward. With this structure, the first guide piece 252eof the cable guide 252 prevents the power cables 239 from being caughtbetween the handle receiving portion 96 and the second recess 97a whenthe bottom cover 6 is fitted on the opening portion of the bottomsurface of the case body 5.

Assume that the CD drive 230 is mounted in the first half zone 221 ofthe lower mount area 104. In this case, as shown in FIG. 43, othersignal cables 253 extending from the CD drive 230 may be caused toextend between the bottom plate 242 of the HDD bracket 241 and thecircuit board 235. The signal cables 253 are inserted between the HDD231 and the front wall 5b of the case body 5. For this reason, in thisembodiment, a second guide piece 252f for restraining the signal cables253 from protruding forward is integrally formed on the second connectorcover portion 252d of the cable guide 252. Similar to the first guidepiece 252e, the second guide piece 252f extends upward from the secondconnector cover portion 252d. The upper end of the guide piece 252freaches the inside of the second recess 97a, and is located between thefitting portion between the second recess 97a and the handle receivingportion 96 of the bottom cover 6. The signal cables 253 are abuttedagainst the inner surface of the second guide piece 252f to restrain thesignal cables 253 from protruding forward. With this structure, thesecond guide piece 252f of the cable guide 252 prevents the signalcables 253 from being caught between the handle receiving portion 96 andthe second recess 97a when the bottom cover 6 is fitted on the openingportion of the bottom surface of the case body 5.

As shown in FIG. 44, the CD drive 230 has a box-like metal casing 257. Aface panel 258 having an insertion port 258a for a compact disk ismounted on one end portion of the casing 257. The peripheral portion ofthe face panel 258 protrudes farther vertically and laterally than thecasing 257. The CD drive 230 is mounted in the lower mount area 104 viathe bracket 232. The bracket 232 comprises a bottom plate 232a coveringthe casing 257 from below, and a pair of side plates 232b and 232ccovering the casing 257 from the left and right sides. Each of the sideplates 232b and 232c has two support pieces 259a and 259b. The sidesurfaces of the casing 257 are clamped between these support pieces 259aand 259b. A plurality of through holes 229 for allowing mount screws 226to be inserted therethrough are formed in each of the support pieces259a and 259b. Each through hole 229 matches one of a plurality of screwholes 257a formed in the side surfaces of the casing 257. With thisstructure, the CD drive 230 is fixed to the bracket 232 by aligning thescrew holes 257a with the through holes 229 of the bracket 232 andturning the screws 226 into the screw holes 257a via the through holes229.

As shown in FIG. 44, the side plates 232b and 232c of the bracket 232have a plurality of fixing pieces 232d. The fixing pieces 232d arefastened and fixed to the boss portions 101 of the case body 5 withscrews 254 shown in FIG. 45. With this structure, the CD drive 230 issupported on the case body 5 in a posture in which the face panel 258faces the right side wall 5d of the case body 5. An opening portion 255through which the face panel 258 is exposed is formed in the right sidewall 5d of the case body 5. As shown in FIGS. 5 and 46A, the openingportion 255 has an opening larger than the face panel 258, and a space248 for causing the inside and outside of the case body 5 to communicatewith each other is present between the edge of the opening portion 255and the face panel 258.

A frame-like rectangular seal member 249 is mounted on the casing 257 ofthe CD drive 230. The seal member 249 is made of an elastic materialsuch as rubber and is located at an end portion, of the casing 257,located on the face panel 258 side. As shown in FIG. 46A, the sealmember 249 covers the space 248 between the opening portion 255 and theface panel 258 from the inside of the case body 5. With this structure,the interior of the case 4 is not seen through the space 248 to improvethe outer appearance of the portable computer 1 and prevent dust andforeign substances from entering the case 4.

As shown in FIG. 46B, when the CD drive 230 is not mounted on the lowermount area 104, the opening portion 255 is covered with a detachableblind cover 256. The blind cover 256 is continuous with the right sidewall 5d of the case body 5 to constitute part of the right side wall 5d.The blind cover 256 is held by the bottom cover 6, and can be removedfrom the case body 5 when the bottom cover 6 is removed from the casebody 5.

As shown in FIGS. 1A and 2, the second half zone 222 of the lower mountarea 104 serves to store large standardized expansion boards 260a and260b which are commercially available. These expansion boards 260a and260b are vertically stacked in the second half zone 222. The second halfzone 222 is opened to the rear side of the case 4 when the rear panel123 is removed. As shown in FIG. 30, when the rear panel 123 is removed,an expansion slot 320 for allowing insertion of a board is opened in therear surface of the case 4. The expansion slot 320 has an opening shapeelongated in the lateral direction and extending throughout the totalwidth of the case 4.

A metal inner cover 321 is mounted on the left end portion of the secondhalf zone 222, when viewed from the rear side of the portablecomputer 1. The inner cover 321 is fixed to the case body 5 togetherwith the power supply unit 150 with screws. As shown in FIGS. 20 and 30,the inner cover 321 has a pair of connector extraction ports 322a and322b through which relay connectors (not shown) of the expansion boards260a and 260b are exposed. The inner cover 321 is located near the rightside wall 5d of the case body 5. An opening portion 323 is formed in theright side wall 5d. As shown in FIG. 20, a frame-like rectangular coversupport wall 324 is integrally formed on the right end portion of thebottom cover 6. The cover support wall 324 is inserted between theopening portion 323 and the inner cover 321. The cover support wall 324has an opening/closing cover 325 for opening/closing the opening portion323. The cover 325 is supported on the cover support wall 324 to bevertically pivotal between a closing position at which the openingportion 323 is closed and an opening position at which the openingportion 323 is opened. When the cover 325 is pivoted to the closingposition, the cover 325 becomes continuous with the right side wall 5dof the case body 5 to constitute part of the right side wall 5d.

As shown in FIG. 25, a fan unit 264 is disposed on the left end portionof the second half zone 222. The fan unit 264 has a box-like fan frame265. The fan frame 265 is fixed to the case body 5 together with themain circuit board 100 with screws. As shown in FIG. 33, the fan frame265 is located below the card storage portion 171 and is adjacent to theleft side wall 5c of the case body 5. The upper surface of the fan frame265 opposes the shield plate 174 of the card storage portion 171 via aspace 263. A shield member 262 filling the space 263 is bonded to theupper surface of the fan frame 265. The shield member 262 has the samearrangement as that of the shield member 92. That is, the shield member262 comprises an outer tube formed by plating the surface of a polyesterfiber with a conductive metal, and a foamed urethane elastic memberfilling the outer tube. The shield member 262 is in contact with theshield plate 174 to fill the space 263, thereby preventinghigh-frequency noise generated by the circuit components 108 on the maincircuit board 100 from leaking through the space 263.

As shown in FIGS. 25 and 33, a pair of insertion guides 266a and 266bare mounted on the fan frame 265 to be arranged side by side in thevertical direction. The insertion guides 266a and 266b respectively haveguide grooves 268a and 268b for guiding the expansion boards 260a and260b in the inserting direction while slidably clamping the expansionboards 260a and 260b when the boards are inserted through the expansionslot 320. When the expansion boards 260a and 260b are inserted along theinsertion guides 266a and 266b to predetermined positions in the secondhalf zone 222, the expansion boards 260a and 260b are electricallyconnected to the expansion connectors 227a and 227b, respectively.

As shown in FIG. 38, the front end portion of the fan frame 265 isinserted into both the first half zone 221 of the lower mount area 104and the upper mount area 103. A second cooling fan 267 for dissipatingheat from the upper mount area 103 and the lower mount area 104 ismounted on the front end portion of the fan frame 265. The secondcooling fan 267 is located inside the exhaust port 210.

With this structure, when the second cooling fan 267 is operated, outerair is drawn into the upper mount area 103 and the lower mount area 104via the vent 211 of the right side wall 5d of the case body 5 and thelower vent 132 of the rear panel 123. As indicated by the arrows in FIG.38, the drawn outer air flows in the upper and lower mount areas 103 and104 toward the second cooling fan 267. In the process of this flow, theexpansion boards 260a and 260b and the HDD 231 are cooled, and thecircuit components 108 and the CPU 109 on the main circuit board 100 arealso cooled. Thereafter, the outer air is exhausted outside the case 4via the exhaust port 210.

As shown in FIGS. 3 and 20, a pair of left and right speaker units 270and 271 are disposed on the front wall 5b of the case body 5. Thesespeaker units 270 and 271 serve to emit sounds reproduced by the CDdrive 230. Since the speaker units 270 and 271 have the samearrangement, the right speaker 271 will be described as arepresentative. As shown in FIGS. 47 to 49, the speaker unit 271 has asupport panel 272 consisting of a synthetic resin material. A largenumber of small holes 273 are formed in the central portion of thesupport panel 272 in the form of a mesh. A speaker 274 is mounted on theinner surface of the support panel 272. The speaker 274 has arectangular metal speaker frame 275 and a black cone 276 supported onthe front surface of the speaker frame 275 and vibrated by a magnet (notshown). The cone 276 opposes the small holes 273. A metal cover 277covering the magnet and a voice coil is mounted on the rear surface ofthe speaker frame 275. The support panel 272 have support portions 278ato 278d for supporting the four corner portions of the speaker frame 275and a pair of boss portions 279a and 279b respectively located on theleft and right sides of the speaker 274. The support portions 278a to278d serve to position the speaker 274 at a predetermined position onthe support panel 272. With this positioning, the cone 276 is located tooppose the small holes 273.

The speaker 274 is fixed to the support panel 272 via a pair of metalpress plates 280a and 280b. The press plates 280a and 280b have baseportions 281 stacked on boss portions 279a and 279b, and tongue portions282 which are in contact with the left and right end portions of thespeaker frame 275. Through holes 284 through which set screws 283 extendare formed in the central portions of the base portions 281. When thescrews 283 extending through the through holes 284 are threadablyengaged with the boss portions 279a and 279b, the press plates 280a and280b are fixed to the boss portions 279a and 279b, respectively, and theleft and right end portions of the speaker frame 275 are clamped betweenthe tongue portions 282 and the support panel 272.

A metal shield plate 285 is interposed between the speaker 274 and thesupport panel 272. The shield plate 285 serves to prevent a magneticfield from the cone 276 from leaking outside the case 4. The shieldplate 285 has a flat rectangular shape covering the front surface of thecone 276. The shield plate 285 has a large number of through holes 286so as not to interfere with sound radiation. Fixing tongue pieces 287aand 287b are integrally formed on the left and right end portions of theshield plate 285. The tongue pieces 287a and 287b are clamped betweenthe boss portions 279a and 279b and the press plates 280a and 280b andare fixed to the support panel 272 together with the speaker 274.

In this embodiment, since the case body 5 is colored in a whitish coloras described above, the support panel 272 is also colored in a whitishcolor. If the support panel 272 has a whitish color, the black cone 276is seen from the outside of the case 4 through the small holes 273 andthe through holes 286, and the front surface of the support panel 272partly becomes black. In order to prevent this, a white woven cloth 288is arranged between the inner surface of the support panel 272 and thecone 276. With the presence of the woven cloth 288, the black cone 276is not easily seen from the outside of the case 4 through the smallholes 273, thus maintaining the portable computer 1 in a good outerappearance.

These speaker units 270 and 271 are detachably attached on the frontwall 5b of the case body 5. As shown in FIGS. 47 and 48, the front wall5b of the case body 5 has notched portions 291 on the left and rightsides of the handle 95. A pair of left and right seat portions 292a and292b are formed upright on the inner surface, of the upper wall 5a,which faces the notched portion 291. The support panel 272 is stacked onthe front wall 5b to cover the notched portion 291 from outside. A pairof left and right mount pieces 293a and 293b stacked on the seatportions 292a and 292b are formed upright on the inner surface of thesupport panel 272. The mount pieces 293a and 293b are fastened to theseat portions 292a and 292b with screws 294, respectively. With thisfastening, the speaker units 270 and 271 are supported on the case body5. The support panel 272 is continuous with the front wall 5b and theleft and right side walls 5c and 5d on substantially the same planes,thus constituting parts of the front wall 5b and the side walls 5c and5d.

According to the speaker units 270, 271 having the above arrangement,since the shield plate 285 is inserted between the speaker 274 and thesupport panel 272, a magnetic field from the speaker 274 can beprevented from leaking outside the case 4 through the support panel 272.Even if, therefore, a floppy disk is placed against the support panel272, information stored in the floppy disk is not destroyed, and theinfluence of a magnetic field on the surroundings of the portablecomputer 1 can be suppressed.

In addition, since the speaker 274 is mounted on the case body 5 whileit is attached to the support panel 272, damage to the cone 276 duringthis mounting operation can be prevented. Assume that the speaker 274 ismounted, as a single unit, on the case body 5. In this case, a mountspace for the speaker 274 is narrow because the main circuit board 100and other various parts are mounted in the case body 5. For this reason,the fragile cone 276 may interfere with a corner portion of the maincircuit board 100 or circuit components mounted in the case body 5. As aresult, the cone 276 may be damaged.

According to the above arrangement, however, since the speaker 274 canbe mounted on the support panel 272 in a wide space independently of thecase body 5, interference between the speaker 274 and peripheral partssuch as the main circuit board 100 and the circuit components 108 can beprevented, thus facilitating the mounting of the speaker 274.

Furthermore, if various speakers 274 having different reproductionfrequency bands are prepared as optional components, a speaker 274 canbe selected and mounted on the support panel 272 in accordance with thetaste of the operator. That is, the speaker 274 can be easily upgraded.

As shown in FIG. 20, a volume control dial 296 is disposed on thecentral portion of the front wall 5b. The dial 296 is located betweenthe left and right speaker units 270 and 271. The dial 296 slightlyprotrudes from the front wall 5b to be operated with a finger of theoperator. The speaker 274 is connected to the dial 296 and the maincircuit board 100 via a lead wire 297. As shown in FIG. 48, the leadwire 297 is arranged through a space 298 between the front wall 5b andthe main circuit board 100. In addition to the lead wire 297, the mountseat portions 105 and the coupling seat portions 106 which are abuttedagainst each other are arranged in the space 298. If the abuttingpositions of the seat portions 105 and 106 and the wiring position ofthe lead wire 297 are on the same plane, the lead wire 297 may be caughtbetween the seat portions 105 and 106 when the seats 105 and 106 areabutted against each other. For this reason, as shown in FIG. 48, thecoupling seat portions 106 extending from the mount surface 7a areextended to a position closer to the bottom cover 6 than the wiringposition of the lead wire 297. With this arrangement, the abuttingpositions of the mount seat portions 105 and the coupling seat portions106 become closer to the bottom cover 6 than the wiring position of thelead wire 297, thereby preventing the lead wire 297 from being caughtbetween the mount seat portions 105 and the coupling seat portions 106when the bottom cover 6 is placed on the case body 5.

As shown in FIG. 50, the keyboard mount portion 7 has an expansionopening portion 300 in the central portion of the mount surface 7a. Theexpansion opening portion 300 communicates with the upper mount area 103and the cord introduction port 27. The main circuit board 100 is exposedthrough the expansion opening portion 300. A cable 301 extending fromthe FDD 140, a power cable 302 extending from the power supply unit 150,and the cord 25 connected to the keyboard unit 18 are inserted betweenthe expansion opening portion 300 and the main circuit board 100.Connectors 303a and 303b and a CPU connector 304 are arranged at aportion where the main circuit board 100 and the expansion openingportion 300 oppose each other. An expansion CPU 315 is selectivelymounted on the CPU connector 304 to improve the memory performance.

A cover 305 consisting of a synthetic resin material and designed toopen/close the expansion opening portion 300 is mounted on the mountsurface 7a. As shown in FIG. 51, the inner surface of the expansionopening portion 300 which opposes the connectors 303a and 303b and theCPU connector 304 is covered with a conductive layer 37. The cover 305has a pair of lock recess portions 306a and 306b. The operator canplace/remove the cover 305 with his/her fingers being fitted in the lockrecess portions 306a and 306b. A flange portion 307 receiving theperipheral portion of the cover 305 is formed on the peripheral portionof the expansion opening portion 300. The flange portion 307 hasreceiving recesses 308a and 308b in which the lock recess portions 306aand 306b are fitted. The lock recess portions 306a and 306b are fastenedand fixed in the receiving recesses 308a and 308b with screws 310. Withthis structure, the cover 305 is fixed to the mount surface 7a on thesame plane, thus constituting part of the mount surface 7a. Note thatrubber caps 311a and 311b covering the screws 310 are detachably fittedin the lock recess portions 306a and 306b.

In this arrangement, when the expansion CPU 315 is to be additionallymounted, the keyboard unit 18 is removed from the mount surface 7a toexpose the cover 305. The rubber caps 311a and 311b are then removedfrom the lock recess portions 306a and 306b, and the screws 310 areloosened to be removed. Finger tips of the operator are inserted in thelock recess portions 306a and 306b to lift the cover 305. With thisoperation, the expansion opening portion 300 is opened, and the CPUconnector 304 is exposed through the expansion opening portion 300. Inthis state, the expansion CPU 315 is mounted on the CPU connector 304through the expansion opening portion 300.

According to this arrangement, in additionally mounting the expansionCPU 315, there is no need to disassemble the case 4 or remove the maincircuit board 100. Therefore, expansion of the portable computer 1 canbe easily realized.

In addition, the cable 301 extending from the FDD 140, the power cable302 extending from the power supply unit 150, and the cord 25 connectedto the keyboard unit 18 are inserted into the expansion opening portion300, and the connectors 303a and 303b for the connection of the cables301 and 302 and the cord 25 are arranged on the upper surface of themain circuit board 100 which opposes the expansion opening portion 300.With this structure, the cables 301 and 302 and the cord 25 can beconnected to the main circuit board 100 through the expansion openingportion 300. Therefore, all the connections between the keyboard unit18, the FDD 140, the power supply unit 150, and the main circuit board100 can be performed from the outside of the case body 5 after thesecomponents are mounted in the case body 5. Accordingly, assembly of theportable computer 1 is facilitated.

In the portable computer 1 having the above-described arrangement, whenan optional unit such as the CD drive 230 or a large-capacity HDD is tobe mounted on the lower mount area 104, the portable computer 1 isplaced upside-down to expose the bottom cover 6. As is apparent, at thistime, the display unit 3 needs to be held at the first position.

Subsequently, the screws 107 are loosened, and the bottom cover 6 islifted to be separated from the case body 5. In this case, since the FDD140 and the power supply unit 150 mounted, as standard units, in theportable computer 1 as well as the main circuit board 100 are supportedon the case body 5, there is no possibility that the FDD 140 and thepower supply unit 150 are removed together with the bottom cover 6 andcables and the like are extracted.

When the bottom cover 6 is removed, the entire lower mount area 104 isexposed to the outside of the case 4, as shown in FIG. 50. When the HDD231 set on the first half zone 221 of the lower mount area 104 is to bereplaced with a large-capacity HDD, the screws of the housing 233 areloosened, and the HDD 231 is removed from the first half zone 221together with the housing 233. The screws used to fix the housing 233 tothe case body 5 are loosened, and the HDD 231 is removed from the firsthalf zone 221 together with the housing 233. Next the HDD 231 is removedfrom the housing 233, and the large-capacity HDD as an optional unit isthen fixed to the housing 233 with screws. Thereafter, the housing 233incorporating the HDD is fixed at a predetermined position on the firsthalf zone 221 with screws, thus completing the mounting of the optionalHDD.

Similarly, when the CD drive 230 is to be additionally mounted on thefirst half zone 221, the blind cover 256 is removed first to open theopening portion 255 of the right side wall 5d of the case body 5. Thescrews of the bracket 232 are then loosened, and the bracket 232 isremoved from the first half zone 221. The CD drive 230 is then fixed tothe bracket 232 with screws, and the bracket 232 is fixed at apredetermined position on the first half zone 221 again with screws.With this operation, the CD drive 230 is supported on the case body 5,and the face panel 258 is positioned at the opening portion 255.

When the expansion boards 260a and 260b are to be additionally mountedon the second half zone 222 of the lower mount area 104, the rear panel123 is removed from the case body 5 to open the second half zone 222 tothe rear side of the case 4 through the expansion slot 320, as shown inFIG. 30. The expansion boards 260a and 260b are then guided to thesecond half zone 222 by the insertion guides 266a and 266b. The leadingends of the expansion boards 260a and 260b are connected to theexpansion connectors 227a and 227b. With this connection, the mountingof the expansion boards 260a and 260b is completed. As a result, therelay connectors of the expansion boards 260a and 260b are placed tooppose the connector extraction ports 322a and 322b. Therefore, when theexpansion boards 260a and 260b are to be additionally mounted on thelower mount area 104, the bottom cover 6 need not be removed, and onlythe rear panel 123 needs to be removed from the case body 5.

According to the embodiment of the present invention, which has theabove-described arrangement, the lower mount area 104, on which optionalunits such as a large-capacity HDD, the CD drive 230, and the expansionboards 260a and 260b are to be additionally mounted, is formed betweenthe main circuit board 100 and the bottom cover 6. For this reason, theentire space below the main circuit board 100 can be used as theexpansion space for the above optional units. Therefore, a sufficientexpansion space can be ensured to allow many optional units to bemounted, as compared with a conventional technique of forming a recessin part of a case and using the recess as an expansion space.

In this embodiment, the lower surface of the main circuit board 100 iscovered with the main shield plate 215, and the main circuit board 100encloses the upper mount area 103 together with the layer 37a on theinner surface of the case body 5. With this structure, anelectromagnetic shield can be provided for the FDD 140, the power supplyunit 150, and the circuit components 108 mounted on the upper mount area103. Therefore, leakage of noise from the base unit 2 can be preventedto realize a reliable countermeasure against electric wave troubles, inspite of the fact that the entire bottom of the case body 5 can beopened.

When the bottom cover 6 is removed, the entire lower mount area 104 isexposed to the outside of the case 4. For this reason, the main circuitboard 100 need not be removed from the case 4 in mounting an optionalunit. Therefore, mounting of an optional unit is facilitated,considering also that the lower mount area 104 is widely open.

Furthermore, since no partition walls for defining an expansion space inthe case 4 are required, the shapes of the case body 5 and the bottomcover 6 can be simplified. For this reason, the mold structure formolding the case 4 can also be simplified, contributing to a reductionin manufacturing cost.

The portable computer 1 having the above arrangement has the secondcooling fan 267 for forcibly cooling the interior of the case 4. Whenthe second cooling fan 267 is operated, outer air drawn through thelower vent 132 of the rear panel 123 is mainly introduced into the lowermount area 104. In this case, when the connector cover 127 above thelower vent 132 is opened, the connector cover 127 overlaps the lowervent 132, as shown in FIG. 26. The presence of the connector cover 127may interfere with introduction of outer air into the lower mount area104. However, since the connector cover 127 has the communicating hole133 which communicates with the lower vent 132 when the connector cover127 is opened, the lower vent 132 is not closed even if the connectorcover 127 is opened to expose the expansion connectors 117. In addition,since the reinforcing plate 135 stacked on the inner surface of the rearpanel 123 also has the communicating holes 137 communicating with thelower vent 132, the ventilation of the lower mount area 104 can bemaintained, and overheat in an optional unit can be prevented.

The portable computer 1 has the display unit 3 pivotally coupled to thebase unit 2. The liquid crystal display unit 41 of the display unit 3 iselectrically connected to the main circuit board 100 via the cable 86for transmitting electrical signals. Since this cable 86 is arrangedbetween the first leg portion 55 and the adjacent projection 35, even ifan electromagnetic shield function is provided for the case 4 and thehousing 40, noise generated by the cable 86 may leak from the case 4 viathe boundary portions between the first pivot leg portion 55 and theprojection 35. According to the above arrangement, however, since theportion, of the cable 86, which extends between the first leg portion 55and the projection 35 is covered with the metal guide tube 90, noisefrom the cable 86 can be shielded by the guide tube 90. Furthermore,since the guide tube 90 is in contact with the layer 37a on the innersurface of the case body 5 and with the layer 43a on the inner surfaceof the housing 40 via the shield member 92, the guide tube 90 can bedirectly grounded to the case body 5 and the housing 40. Therefore,leakage of noise from the boundary portions between the first legportion 55 and the projection 35 can be reliably prevented, and electricwave troubles can be more effectively reduced.

The present invention is not limited to the above-described embodiment.Various changes and modifications can be made within the spirit andscope of the invention.

For example, in the above embodiment, the bottom cover and the rearpanel are separately formed. These parts may be integrated so that thebottom and rear surfaces of the case may be continuously opened.

In addition, the portable electronic apparatus according to the presentinvention is not limited to a portable computer, and the presentinvention can be equally applied to other apparatuses such as awordprocessor.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, and representative devices shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. A portable electronic apparatus wherein aplurality of card-like electronic components are loaded/unloadedtherethrough comprising:a case having a bottom surface, an upper surfaceopposing the bottom surface, and a peripheral surface continuous withthe bottom surface and the upper surface, the peripheral surface havinga card insertion port formed therein; a circuit board housed in saidcase to be parallel to the bottom surface and the upper surface, saidcircuit board having upper and lower surfaces; and first and second cardstorage portions which are respectively arranged on the upper and lowersurfaces of said circuit board said first and second card storageportions being arranged so as to oppose each other across said circuitboard and respectively having an opening portions continuous with saidinsertion port, said card-like electronic components being removablyhoused in said first and second card storage portions through saidinsertion port and said opening portions, and said card-like electroniccomponents being parallel to said circuit board, when said card-likeelectronic components are housed in said first and second card storageportions.
 2. An apparatus according to claim 1, wherein said first andsecond card storage portions respectively have first and second cardconnectors to which the card-like electronic components are electricallyconnected, and first and second housings covering the first and secondcard connectors and constituting guide paths for guiding the card-likeelectronic components to the first and second card connectors incooperation with said circuit board, the first and second housingshaving the opening portions.
 3. An apparatus according to claim 2,wherein said case has a card cover for opening/closing the cardinsertion port, and the card-like electronic components stored in saidfirst and second card storage portions are located deeper in said casethan the card cover.
 4. An apparatus according to claim 3, furthercomprising an inner cover for covering a space between said first andsecond card storage portions from the inside of said case, said innercover having an introduction port communicating with the openingportions of said first and second card storage portions.